cabdriver vs hack driver

cabdriver and hack driver both are nouns.

Word	Noun	Adjective	Verb	Adverb
cabdriver	Yes	No	No	No
hack driver	Yes	No	No	No

As nouns, cabdriver and hack driver are synonyms defined as:

Other synonyms of cabdriver include cabby, cabman, hack-driver, livery driver, taxidriver, taximan.

cabdriver (noun)	hack driver (noun)
someone who drives a taxi for a living	someone who drives a taxi for a living